


Hidden Designs

by NanaMun



Series: The Commander and the Biotic Detective [2]
Category: Mass Effect, Sherlock (TV)
Genre: An excuse to have Mordin and Sherlock in the same room, Biotic!Sherlock, Citadel, Commander!John, M/M, Moriarty is sort of a Shadow Broker, Mycroft is sort of an Illusive Man, omega - Freeform
Language: English
Status: In-Progress
Published: 2014-10-05
Updated: 2015-07-21
Packaged: 2018-02-19 23:12:32
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 9,344
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2406410
Author URL: https://archiveofourown.org/users/NanaMun/pseuds/NanaMun
Summary: <blockquote class="userstuff">
              <p>A lost Commander temporarily without ship and crew on a space station gets involved in helping solve cases with an alluring biotic detective. What could possibly go wrong?</p>
            </blockquote>





	1. Citadel I

**Author's Note:**

> The official start to what I've been outlining for months.  
> Keep in mind, if you're not trained in Mass Effect lore, you're about to be.

**Summary for the Chapter:**

> Sometimes he wondered if the John from years before would even recognize him. Sometimes he didn’t even recognize himself.

_Citadel: Year 2183_

It was small in scale, though glorious in its replication. John Watson stared in admiration and disappointment. Ten years ago this was his future and now…

            “Welcome back to the Citadel Presidium, Commander Watson. How may I assist you today?” The glow of the VI refocused his attention. He gave a brief clearing of his throat, quite aware that the hologram Intelligence didn’t pick up his awkward stance in front of the Relay Monument. He had only been back but an hour and already felt helpless and misplaced. A sharp pang in his left shoulder provided him the incentive to complete his task and be on the first ship back home.

            “Might I get the directions to the Embassies please?”

*

“Ah, Commander Watson.” Captain Anderson stood as John entered a look of relief blanketing his face. To John, it looked as if he was interrupting a rather unpleasant conversation with a turian.

“Captain.” Watson nodded curtly. To get this over and done with would have been a blessing, but things hardly ever went quick and swift in the career he chosen.

“Glad to have you here, safe and sound. Take a seat.” Case in point.

The turian, clearly seeing that their conversation was over, shot a glare at the Captain before setting to march out, his pointed face set and his small ridged nose twitching. The slide of the automatic doors behind him was cause for the Captain to continue.

“It’s good to have you back, son. I can’t say it enough.” He paused as if expecting John to concur with his sentiment. John couldn’t find it in him to agree. The trip over had been excruciating. Of course there was the pain of his injuries, but the knowledge that this was it. The loss of the ship, the crew, his freedom to travel and take on the missions, providing medicine and assistance to in need colonies was gone.

All of it.

 John sat down, grinding his teeth at the agony of his leg. He hated the constant reminder of his relieve.

 

Reading his mood, the Captain gave a tired sighed, “It’s not over yet, Watson. You’re still to see a counselor and report to medical. And the ship is now yours.”

“With all due respect sir-“

The older man held up a hand before he could go farther, “Listen, it wasn’t your fault. And no one, not I or the Alliance is going to hold it against you. What happened there couldn’t have been predicted.”

John felt the sudden rush of shame. All those bodies…

“But the casualties-“

“Were not of your making.” The Captain seemed to ponder for a minute, “I know right now you’re wondering why you’re here and not back at home,” The older man schooled his features, preparing his next words, “Your history with Alliance, the brief time you spent during your… _unofficial_ missions, that’s something I have taken into consideration after recent events.”

John felt the tension in his shoulders at the thought that the Alliance would need him for anything else. He just wanted peace, to forget. There won’t be the Mission or the lives to save, but there also wouldn’t be loss and regret. John blinked away the memory of a glassy, blank stare of the last man he could ever fully trust, and straightened his spine meeting the Captain’s gaze.

“Sir?” He encouraged him to continue.

“I’m asking you this, Commander, not ordering.”  There was a brief silence before he went on, “I have reason to believe that you may be needed for a few small missions,” He held up a hand before John could cut in, “Nothing like your recent missions, this is… _unofficial_ as well. Though, I can’t guarantee that it’ll be as dangerous or even as stimulating…”

John considered. He still ached and his mind and body was weary, but if the Captain was offering something like this so close after what had happened, there must have been something else he wasn’t being forward about, “And what is this mission?”

“To be honest,” He murmured, “Accompanying a scientist –though he won’t be calling himself that –on a few local investigations.”

“So I’m…babysitting.” John wasn’t sure whether to be relieved or insulted.

There was a deep chuckle in reply, “I’m sure it’ll initially feel that way, but he’s more work than merely keeping out of trouble.”

“Would I…” John cleared his throat, “Would we be leaving the Citadel?”

The captain gave him a knowing look, “The tasks you will be accompanying him on are local, yes, but if you’re asking if you still have access to the _Reichenbach_ then I can answer that with an emphatic yes.”

John didn’t realize the weak, shaky breath he released until he felt the comforting pat on his rounded shoulders.

“I mean this, Commander,” Captain Anderson assured, “The ship is yours. Your Captain would have wanted you to have it. He spoke highly of you, but it wasn’t just his words that gave you this ship. It’s your work and your accomplishments. The lives you saved, son…” John kept his eyes fixed over the Captain’s shoulder but didn’t fail to listen intently, “I know you’re not ready to go back out there, but you can still do good work until you are.”

“And my condition, sir…” John wouldn’t allow himself to continue.

“There is no condition, Watson.” Was the solemn reply, “You should only face and acknowledge the events that have happened.”

*

The pulse of the Citadel wasn’t anything like the gentle hum of the _Reichenbach_. John lay in bed, back flat against the plush cushion of the generously spaced bed in a luxurious room somewhere in the residential towers provided for all military visitors. The bed was too wide, the room too posh and the ground too solid beneath his feet, even for a massive space station. He couldn’t sleep. There would be no peace for him tonight. With a resigned groan, he sat up in bed. If he wasn’t going to be resting for the night, he may as well get to know the place he would reside. He strolled past the residential towers, through the markets and stopped in one of the hubs attracting party-goers and those looking for a good time. Many asari dressed in glossy, tight suits, human men and women smiling broadly at the prospect and novelty of being around alien beings, and even the rare krogan, big in form and clearing paths in the crowd. This wasn’t necessarily John’s scene, but the liveliness of the hub was contagious nonetheless.

He took to people watching at a bar somewhere by where he was staying, making sure to try a new drink, though he couldn’t be sure if it was something he may have had before. After all, he spent so much time on a ship, landing on foreign worlds, eating new foods and talking to distant strangers that he may have lost track of a simple drink in its taste and color. He figured as long as it wasn’t one of Earth’s poisons, it was something new.

Without meaning to, he caught the eye of an asari across the bar. The hue of her blue skin glowed under the many shining lights off the walk-way by the bar and her suit hugged every curve of her body just the right way. She smiled coyly at him, sipping her drink. He smiled politely back, but made no move do anything. Perhaps in a different time, under different circumstances…

He couldn’t picture himself right now grabbing a stranger and taking a tumble back into his bed for a night of debauchery. In the past, it was something he learned to get accustomed to, knowing there was no time for dating or sparking relationships between missions. And especially after the heartbreak of his previous partner, he wasn’t sure he could even try again, let alone now. He couldn’t deny that the ache of loneliness was just a bit rougher, made him just a bit colder without the missions and traveling. He shook that thought off, instead choosing to steer to the reason he was here in the first place. He found it particularly odd to find the message on his private terminal from Captain Anderson, requesting him to visit. What was even more peculiar was that somehow he was already aware that the _Reichenbach_ was ordered directly to the Citadel instead of Earth. The Captain still had the _Normandy_ and its missions, so why had he taken the time to dock and request a meeting? Wasn’t this something an Admiral did or those based on Earth? He was almost certain this had to do with it being _unofficial._ At least that he could feel comfortable with. He knew _unofficial,_ he could do _unofficial._

The asari girl caught his eye again, though this time with exasperation. It appeared she was waiting for his approach. He sighed, finishing his drink. With a pat on the bar counter, he pushed off to leave, only pausing when his thigh pulsed in pain.

 

*

“We have a session in two days’ time.”

John didn’t know how to respond to that. Nod? Say yes?

“Will you go?”

That surely startled him out of his thoughts, “I see no reason why not.” His therapist didn’t appear fooled, “You don’t think I will.” He concluded. It’s true, he hadn’t thought of returning. He didn’t see the point in it. He wasn’t going to talk about the last mission, nor was he ready to accept that _he_ was the reason for the bum leg. No matter how much medi-gel was given or how many scans he received, it did nothing. And the therapy wasn’t going any better.

“I’m not sure.” He eventually answered honestly. Three visits and he shouldn’t have been expecting much, but there was still a sense of _stagnation_ sitting in this room, talking to the well-meaning asari therapist, feeling that thrum to move, the need to feel a ship beneath his feet and having a destination to go to.  He wasn’t meant to be sat here, droning on about his day or thoughts or regrets or mistakes. He wasn’t meant to be invalid.

“You have a lot to say, John.” Sometimes John questioned whether or not asari had telepathy without a psychic connection, “You’re just not willing to share. Your visits are becoming straining, and it isn’t productive for either of us. You’re a practical man and any practical man would call this a loss and not return.”

“And do you recommend that then?”

She hesitated before leaning forward, “In my brief years of counseling humans, I can say that sometimes the unconventional approach is the best one. I recommend what you feel comfortable with. You are not willing to speak now or to push past your trauma and that will take time. Perhaps the last thing you need right now is to be reminded of what you lost and work up to how much you want to get it back.” With that she leaned back, adjusting her position in her chair, “And when that time comes, let me know.”

*

            _John,_

_I heard about what happened at Artemis Tau. I’m so sorry. Those were our people out there that were killed, that we lost and it hurts to know you were there to see it. Thank you for letting me know you’ll be on the Citadel. I’ll try to meet you there the moment I get a chance. I know it’s the wrong time to say, but I miss you and I know it’ll do us both some good to catch up and enjoy ourselves._

_See you soon,_

_Kaidan_

*

            It had been a lousy morning for him. Rereading the message reminded him of a past so long gone it felt like a different life. This was not what he needed now. Finally down to the last unread message, John was happy to see that at least this particular old friend didn’t come with painful emotional reminders. It was quite a jovial message requesting they meet at the Huerta Memorial Hospital where he was directed by Captain Anderson to introduce him to the scientist he’d be helping.

            He gathered up the little energy he had and set off to his journey. The hospital wasn’t as far a destination as assumed, so when his feet finally settled outside the shuttle, there was a brief moment of hesitation. He was about to meet someone he hadn’t seen, let alone had consistent contact with since when he was a fresh faced and determined young man with a need for adventure. Sometimes he wondered if the John from years before would even recognize him. Flashes of black hair and earnest brown eyes flittered in and out of his memory. He had to take a breath. Sometimes he didn’t even recognize himself.

            The hospital was bustling. Beings of all walks of life waited patiently for assistance or brushed by John in medical coats. John, feet away from the lift he came in, glanced around appreciatively. This was certainly more advanced since his time in hospitals. He stood in what could only be described as a lobby. Its space was generous, and the set-up was open with walls of glass looking over the station. The view was breathtaking. John could see just far enough to notice the slight curvature of the Citadel’s open arms. It really was a beautiful design.

Yards away from John, a few hassled human doctors muttered solemnly to themselves. Of the group a husky man possessing a boyish face looked up and caught his eye. They recognized each other immediately. John couldn’t withhold his smile.

“Mike.” He said, surprised at how pleasant and happy he sounded.

“Oh, John!” Mike’s mouth formed into a comedic, round shape, the group of doctors around him forgotten as he approached his old friend, “How have you been? I mean, I know how you have been, but it’s been awhile, or rather years-“  He went on enthusiastically. When he finally stopped to catch his breath, he continued, “Anderson said I was going to meet a Commander Watson, but mate I had no idea it would be you.”

John blinked in confusion, “Wait, you didn’t know it was me?” Mike nodded, looking rather bashful at the admission, “You sent me a personal message.”

“Yeah, yeah.” He waved a thick hand about, “It’s been a long few days and honestly with everything that has happened since we last seen each other, I figured that maybe seeing you again would be having blind faith.” He made no attempts to sound bothered by his honesty, but if there was something John didn’t forget, it was that Mike always was a caring and committed friend, so of course he knew it bothered him more than he let on.

John nodded, without commenting. It had been years, but he still wasn’t capable of facing what he left behind.

“Just seen Kaidan a few days back.” Mike continued, causing John’s heart to jump in his throat, “He looks good. Doing okay, I guess. Still gets those maddening headaches, but his biotics have gotten better.” Mike went on innocently, apparently unaware the current topic was one John had been trying to avoid.

“That’s good.” John avoided eye contact, using the sites of the Citadel as a distraction.

“He knows you’re back, right?” This time Mike watched him closely.

With a thorough clearing of his throat, John nodded, “Yeah. I was sure to let him know.”

“Good. He still talks about you.” At the confession, John’s eyes shot back to Mike’s. His friend’s face was schooled, showing no signs of what could have been shared days before. In fact, he chose that moment to change the subject, “So, I’m supposed to be showing you your new assignment. I’ll be honest, I was surprised Anderson approached me of all people, but seeing how it’s you, it all makes sense now.”

“About this new _assignment_ …” John’s eyes narrowed.

Mike snorted, “More of a chore, I’ll admit, but John, you have always been a man willing to face a challenge.” He joked lightly, patting John encouragingly on the shoulder.

“That’s not reassuring, Mike.”

“I suppose it isn’t.” Mike said, thoughtfully, “But seeing as you’re here until your ship is repaired, this mission would be a successful distraction.” He tilted his head towards the other side of the waiting lobby of the hospital, “Come on, let me take you down to the labs.”

*

            “It’s not so bad, really.” Mike continued once they exited the lift, “Being away from Earth has actually gotten to be fun, though sometimes I find myself debating about the vaccination process of Batarian viruses with a group of Salarians and ask myself what has become of my life.” He chortled.

            John chuckled along, glad that Mike had actually taken a direction he was comfortable with, “It seems life has treated you well.” He observed.

            “Yes, yes,” Mike rolled his eyes, “I’ve gained quite a bit of weight since meeting the wife.”

            “I mean it.” John was earnest in his observation, “You were always so fearful about going out into the black.” Of all his friends, it was Mike who feared the planets, the colony attacks and random plagues that took on the first space travelers from Earth. He had always been the one to research the most gruesome and frightening tales of failed missions, of ships found, striped with nothing found of the crew of their supplies. It upset John that he left and never had taken the chance to actually check up on his friend over the last few years.

            “I was.” Mike agreed, “But then I made some friends. Speaking of which…” He stopped walking, causing John to cease next to him. They stood next to a door labeled **Barts Lab A.** “He should still be in. Last time I checked, he was complaining about some case or the other he was helping with.” Mike mumbled to himself. With a fond chuckle, he stepped towards the door, not hesitating when it swished open to reveal an advanced lab with a few instruments cast about, but otherwise empty.

            “Oh,” Was Mike’s disappointed response. He turned towards John with a look of pride, “Guess Sherlock solved the case sooner than expected.”

*

 

            John was tired.

            After a long lunch of conversation and catching up, then taking in some more sights of the Citadel, only to walk some of the way home in a sea of clashing thoughts from the past and a nagging curiosity on what his actual assignment consisted of, John was ready to take something strong and call it a night.

            Mike had been forgiving of John’s lack of contact over the years, but it didn’t mean he was letting John off easy. The subject of Kaidan was brought up again. Last Mike heard, Kaidan had just ended a short-lived relationship with some woman Mike hardly knew. John had swallowed the last of his dinner at the new information, feeling the numbness spread from his chest on, yet he smiled politely and let him speak.

            Now back at what was temporarily his home, John kicked off his shoes, while absently rubbing the rigidity out of his left shoulder. It took the time of him inhaling and exhaling to realize there was an intruder in the midst. Feeling his body automatically stiffening, John’s eyes searched the room in front of him. Nothing could be seen, even in the soft glow of the space station’s lights, so he was left to his instincts. He was sure to know all the best corners and blind spots of the residence, so in the dark, he listed them with efficient speed, starting with the kitchen. Taking a cautious step forward, he let his eyes adjust to the dark and approached at an angle that kept him outside the reach of any intruder hidden in the nook between the divider of the dining room and kitchen. His eyes caught sight of no one. Next was the den. Turning on his heels, he was ready to approach, though the sight of the shadow in the den had stopped him.

            John planted his feet, pushed his shoulders back and stared at the dark space, “Who are you?” He kept his voice low, short of a growl.

            “Lights.” A deep voice rumbled and the den light switched on. There, sitting rather comfortably in a well-fitted suit was a man, watching him with casual interest. He said nothing at first, letting his eyes trail down the length of John, silver-like irises flickering the plane of his body as if he was rapidly reading the words from a rather riveting book, “John Watson” His voice was smooth and non-threatening, though that wasn’t enough to cause John to relax. He had seen many men and women who spoke softly, but killed more viciously than any other suspecting enemy.

            “You haven’t answered my question.” John kept his ground and gave the intruder no sign that he was trusted.

            “Interesting,” The man smirked, full lips pulling up slightly. His eyes seemed to glow in interest. John felt bewildered at the sudden thought of a child with a new toy. The man stood with a graceful air about him, pulling himself at full height. He had inches on John, nothing that was difficult to handle. John tensed at the sudden move, though the man didn’t seem to be bothered, “Sherlock Holmes. I believe Commander Watson that I’ll be taking you on as my new assignment.

            Sherlock….? The name to lingered and bounced around his head, before he realized that this man was the same person he was supposed to meet earlier. Surely Mike would have told him that this man would be waiting for him. He wouldn’t have sent him blindly to a soldier’s (a known N7) house. It screamed danger, even to civilians. But as soon as the thought settled in, John realized what was actually said and for the first time since seeing the stranger in his house, all tension left his body.

            He was supposed to work with this man on a new assignment, but John was not mistaken in what he heard, “ _I’m_ your new assignment?”


	2. Citadel II

**Summary for the Chapter:**

> This wasn’t something he was supposed to be doing, but sitting in a tenement letting the guilt and his injuries eat at him was not doing his mind any good.

**Notes for the Chapter:**

> I'm attempting weekly updates for the fic, so if all goes well with writing then I'll see you next week!  
> Also, apologies for any typos. No beta, I'm afraid.

John was not mistaken. The man looked _bored._

            “I cannot be an assignment. It makes no sense.” He went on for the umpteenth time, “I’m technically on shore leave, if anything. I’m here so my ship can be repaired, not so some pompous twat who breaks into houses can prod at me.” He was annoyed. How dare Anderson sit there and lie. How dare he be told that he would be babysitting when he was probably under some investigation? They couldn’t have thought he had anything to do with the Alliance ship ambush, the loss of a captain. They couldn’t have thought that-

            “No one thinks you’re behind this.” Sherlock said with a scoff, “Now sit down. Your pacing is giving me motion sickness.”

            “Shut up.” John growled, “Better yet, piss off. I can refuse you. You’re not here under Alliance orders or Citadel Counsel Decree for that matter, so I strongly suggest you leave me alone.”

            With a huff, the man was standing up again, “Tell me Commander Watson, have you always been this calm when caught off guard?”

            John stared at him, bewildered, “What?”

            “You’re an untrusting man. You memorized the entire layout of this place, knowing every nook and cranny that an enemy can hide. You were trained and have often fought in unofficial skirmishes that the Alliance would dismiss without hesitation, so you are bound to have some enemies. You witnessed your captain get assassinated after being lured by what was an Alliance ship, only to be targeted yourself. You know there’s a target on your back, and you’re not afraid.” The man stalked around him like a big cat, “You entered the residence and instantly knew you were not alone and realized you were right, yet here you are, bothered yet unperturbed.”

            John blinked, mouth opening, then closing, only to open again, “How did you-“

“I observed.” He said and then added after a pause, “And I hacked the system and read your file.”

John couldn’t wrap his head around what was happening. Feeling the air leave his lungs in a hasty rush, he collapsed on one of the free lounge chairs he had assumed was more for show than actual sitting. His hands scrubbed the weary expression off his face and with a deep breath he rested his elbows on his knees and finally regarded the man in front of him.

“Who had you read my file?”

“I was curious.” The man responded without a scant of shame.

“Curious…” John let the word trail off. And what could exactly ignite his curiosity if no one asked of him to look John up. The man waited, as is he knew it would take John a moment to collect his next words. He was right. Finally, with all thoughts in order, John spoke up again, “I was supposed to meet you earlier today.”

At that, the man’s brows shot up, “Pardon?” It was nice to see him confused for once.

“I was set up to meet a Sherlock at a lab in Huerta Memorial Hospital.”

“I was there briefly, but something much more interesting came along and I took my leave.” He smirked as if in on a private joke.

“I was referred to you by Captain Anderson, so it’s safe to say in some capacity you’re working together with him.”

Sherlock’s bland expression contorted to disgust, muttering something under his breath, before speaking up, “You were referred to me because someone knows me too well and was aware I’d take interest during your stay here. I suppose it was a way to expedite our meeting to something more civil rather than-“

“You breaking into my flat?” John finished, earning an amused smirk in return, “So why are you interested then?” John questioned, as curious as he was put off, “in me, I mean.”

At the question, Sherlock took to pacing, “There was an assassination of a captain here on the Citadel not a few days ago. The maneuver in the kill was precise and thorough. It was no murder, not a crime of passion. This was an execution of politics,” His cat-like eyes slid to meet John’s, “or war.” John refrained from rolling his eyes at the theatrics. He motioned for him to go on.

“Your captain suffered a similar demise, but something quite curious did _not_ happen.”

“And that was…?”

“You survived.” John’s heart picked up speed. He knew what the man meant, “You were an unsuccessful attempt. Any idea why, Commander Watson?”

John’s jaw tightened. He could find no words, so he stiffly shook his head.

“Hmm,” the man paced again, “An Alliance ship and an ex-Alliance sniper. Time of kills within days of each other it would seem and both captains having history in meddling in affairs outside the realm of Alliance.”

John’s jaw ticked.

And Sherlock noticed.

“Want to answer my question now, Commander?”

He didn’t know what to say. Clearly, Sherlock had hacked more than just his file, but what did he know? Who did he know to get that information? Like he said, they operated outside the Alliance, so nothing was logged.

_Unofficial._ He worked as an _unofficial._

“You’re N7.” Sherlock finally spoke up, “It really wasn’t a stretch to figure that out, what with who the captain of the _SSV Reichenbach_   was,” Sherlock droned on, “N7 operatives are trained at the highest level of proficiency, it that right Commander?”

“I cannot disagree.” John rumbled derisively. Sherlock continued as if his question was rhetorical.

“So there had to be opportunities and chances for extra-curricular missions. Corsair missions perhaps?” John started at the word ‘Corsair’. Very few people knew of those assignments, let alone an intruder who may have been too intelligent for his own good. John was aware there were things of his past he kept well hidden, but it was certainly clear that this Sherlock was just as under the radar as he had ever been.

“Who are you?”

“I answered, Sherlock Holmes.”

“I mean who are you _really_?”

Sherlock considered the question, “I’m a consulting detective for the Citadel, specifically the authorities.”

“So you work for C-Sec?”

Sherlock scowled, “I _consult_ , I’m neither employed nor do I answer to them. They seek me when they are done tripping over themselves to solve menial cases.”

“So not working for the Citadel Counsel then?”

“ _Dull._ ” The man muttered with what appeared as much scorn there could ever be in a word. John almost allowed what could have been described as a smile to twitch on his lips. He didn’t know what to make of this man.

“So you’re interested in me because you want to figure out if there is a connection between what happened here and to my crew.”

“’ _If’_ was a matter of a few hours ago, ‘ _why’_ is a matter of now.”

“That’s a stretch.”

“Only to the stupid.” He rolled his eyes at John’s raised eyebrow, “Oh, you know what I mean.” John didn’t.

It was better to dismiss the insult, “You want information from me then. Seems you have everything figured out.” With a sigh, he stood up, groaning when the pang in his leg intensified. At the sign of pain, Sherlock’s eyes narrowed, yet no words were spoken, “Now that you’ve got everything, I think I’ll call it a night. I’m still a bit tired from nearly being killed and all.” He was already to the doorway of the den when Sherlock spoke up.

“I would still need you to answer some questions.”

“Fantastic.” He didn’t turn, “How about tomorrow at the place we were meant to originally meet.”

“Tedious,” was the apt reply from the intruder, “Meet me at the Baker Street Towers. 221 B.” He said with a graceful gait towards the front door.

“Okay.” John mumbled tiredly, “What time?”

A loud swish and click of the door closing was the only answer he received.

*

 

He had no idea what he was doing.

This was dangerous. This was treason. If any other operative knew or even suspected…

But he had never let such thoughts like that stop him before. This was why he was an N7 operative in the first place. It was why he was the Commander of the _SSV Reichenbach_. It was why he survived when he was targeted by dozens of men and women.

This wasn’t something he was supposed to be doing, but sitting in a tenement letting the guilt and his injuries eat at him was not doing his mind any good.

And if he was being honest with himself, he wanted to know. He had been dying to know. What happened and why.

And if this man could help in any way possible…Even if it meant dissecting all the things John had done, then maybe…

The Baker Street Towers weren’t much of towers at all. They were 6 floors at best, but the grandiose air of them made them look more intimidating. Whoever this Sherlock was, his work must have been well received. This was surely not a cheap estate to occupy. John entered the property’s lobby, bypassing the adverts and front desk, before moving past the doors leading to the actual residences. Inside was one door labeled **221A,** with a lift across from it. John figured he must live a floor or so up, so he called the lift and waited. He was surprised to hear a pleasant trill before the elevator spoke.

“State your name.”

“John Watson.” He answered automatically.

“State your purpose.” The elevator replied.

John had to think on that one. What was his purpose? He opened his mouth to speak, only to hear a familiar deep voice yelling out in annoyance.

“Oh don’t be tedious, Sherrinford. Let him in.”

“Affirmative, Mr. Holmes.” The intelligence said, “Welcome John Watson. Please, step inside.”

“Er, thanks.” He answered with a quizzical raise of the eyebrows.

Once inside the lift moved on its own accord before stopping briefly and opening silently to reveal a massive space. There floating in front of the lift doors was a spherical shaped V.I. hovering at the level of his head and glowing a color that reminded John of Sherlock’s eyes.

“My apologies, Commander Watson. Mr. Holmes has informed me of your status as an Alliance marine of exceptional duty and-“

“Oh, do shut up.” A disheveled Sherlock made himself known from a hallway somewhere in the depths of the massive apartment. He was comfortably dressed in what appeared to be a thin house robe and a t-shirt and pajama bottoms, bare feet slapping on the ground as he approached John, “I could never program him to be less of a moron, so this would have to do.” He glared at the orb, “Commander, you can join me in my lab.” With that he turned with a flick of his robe as if it were a cape. John couldn’t keep his snort to himself, but nonetheless followed.

He nodded to the sphere, “Thank you and I apologize for his behavior.”

“No apologies necessary.” The V.I. replied calmly, “Mr. Holmes knows not of his lack of social intelligence.” John didn’t try covering his laugh. He watched the orb float off into another area of the flat.

When John finally stepped into what was actually a kitchen, he caught sight of the man at work, eyes watching a screen in front of him and scowling.

“So…Sherrinford, huh?” John said lightly.

“It’s a family name.” Sherlock answered with a twitch of his lips as if refraining from smiling.

            “Like Sherlock?” John teased.

            He looked far too elegant for his own good, standing there in just pajamas and a robe. He shot a quick glance at John, seeming to consider his words before he spoke, “Sherlock’s a girl’s name.” was his response.

            John couldn’t contain his laugh. This whole ordeal was becoming too much for him to process. It might have been driving him a bit insane. It was quite alarming and pleasant to see the younger man relaxed and in his own space, never mind the way he actually smiled at John’s amusement. In this place, he was more human. Not much to compare it to, seeing as the night before he had broken into John’s place and waited with too much ease for such a man to do so.

            “You must be dangerous.” The thought finally occurred to John. He was either dangerous or most certainly unwise. Who breaks into a house only to invite the intruded to his?

            “And if I am?” Sherlock responded with no pause. This had to be what he defined as a normal conversation.

            “Well, I suppose I wouldn’t be bored.” John shrugged. What else was he to do if such a person was dangerous? If John weren’t being too bold, there were times when he had been quite dangerous as well.

Danger had never been a problem before.

            Sherlock watched him with knowing eyes, but said nothing.

            What followed was a brief moment of silence as John watched Sherlock continue what he was doing. He finally took notice of all the old looking flasks and what appeared to be a century old microscope. He originally considered if that needed to be in a museum, then reassessed the question and reflected maybe it had already been. Sherlock was currently using what the present day microscopes med or science students saw in university or science labs. Whatever was under the scope was projected right in front of Sherlock –a flickering holographic screen showing what appeared to be cells.

            “Working on something special?” John asked.

            “Krogan genophage.” Sherlock said shortly without looking away from the screen.

            John balked, “What?” He had to have misheard him. There had been no scientific cures for krogan genophage, not that anyone was looking, surely not salarian or turian, “You’re joking.”

            Sherlock looked comically offended, “I most certainly am not.”

            So, you’re telling me you’re trying to find a cure?”

            “Cure?” Sherlock scoffed, “Hardly. This isn’t just some evolved virus or a debilitating disease, Commander. This is made by the hands of scientists. I’m not looking for a _cure_ , I’m concluding how to create a reversal.” John couldn’t believe what he was hearing.

            “I’m certain C-Sec isn’t desperate for figuring out how to fix the krogan genophage now.”

            “They’d be wise to do so.” was the reply he received.

            “And what’s that supposed to mean?”

            Looking particularly bothered, Sherlock rested his palms on the expensive kitchen counter, shoulders hunching as full lips pursed in thought. Finally, after a moment, he spoke, “Imagine you were to discover that the white cells in your body were attacking that which weren’t infectious diseases. Your doctor tells you that surely what needs to be done is to kill off every single white cell. Problem solved, right? Only now, you’re finding that with no white blood cells, your body can’t sustain its health. Tricky, without an immune system and all.”

            John hadn’t suspected he could become more befuddled by Sherlock himself. The krogan race was known for being a people of violent history. John didn’t know much krogan, but he had seen enough of them in his skirmishes with mercenaries to conclude that a dozen of them were nearly impossible to overcome. To imagine hundreds if not thousands of them in the krogan rebellions he heard about in his galactic history courses from way back, genophage seemed more like an inevitability rather than a harsh execution of a bioweapon.

            “Are you comparing krogan to white blood cells?” John finally piped, shaking himself from the direction of his thoughts.

            “Possibly,” Sherlock gracefully shrugged, “But the point to be made is that with an immune system that virtually doesn’t exists, what’s to keep from sustaining the fragile system we have now?”

            “Like another Rachni War, you’re saying?” John was happy he was able to pull up his history, quite proud in fact. He remembered that was the beginning of the krogan problem. The rachni were a powerful and intelligent species that the salarian, asari and turian race could not defeat. It was with the discovery of the krogans that the war turned around. The krogans had been suffering from their own civil war and were saved, given new technology and a planet, but there was a price for it. Their brute services were needed. They defeated the rachni and with that had a foot hold as a force in the galaxy.

            “Something worse I’d wager.” Sherlock said solemnly.

            Before the response could be questioned, there was a humming trill next to John. He turned and nearly jumped at the site of Sherrinford floating near his head.

            “My apologies for the interruption,” Sherrinford’s pleasant voice spoke, “Gregory Lestrade from Citadel Security has arrived.”

            Sherlock glared at the orb, “You let _him_ in?”

            “The frequency of his visits is at an average of 3.24 times a week. Your authorizing him permission in the residence is an average of 70.6% and 92.35% when you’re in good spirits. Seeing as you are enjoying Commander Watson’s company, I was merely conserving your time-“

            Sherlock swatted at the blue sphere, “All right, all right.”  

            It wasn’t long before a man taller than John, but an inch or so shorter than Sherlock had entered, looking a bit tired, but healthy nonetheless. He wore the uniform of a c-sec officer with power, but judging by the meek expression on his face, wasn’t likely to wield it.

            “Sherlock, there’s been another assassination.”

            At the sentence, Sherlock’s experiment was long forgotten, “Like the sniper.” He claimed, rather than asked.

            “Yes,” the officer said with an aggravated swipe of his short, gray strands, “The commander of the previous victim, though this one was a poison slipped into a drink at Chora’s Den.”

            “Could there have been any other place?” Sherlock scoffed, before turning to John, “You’re luckier than you think, _Commander._ ” John blinked at the suggestion. Did this mean that whoever was going after him was going after all captains and their near ranks? Or was this victim another operative in the unofficials?

            Before John could even ask the question, Sherlock was ordering Sherrinford about his suit, “Time of death?” He threw over his shoulder at the officer. The man didn’t seem bothered by the fact that Sherlock was throwing off his robe as he was climbing the stairs on his way to what must have been his room to dress.

            “An hour ago.” The officer said with a raise of his voice. He caught John’s gaze, “So sorry to interrupt. I’m sure you know how he is with the Work.” At John’s puzzled look, his expression softened. Extending his hand, he started over, “Gregory Lestrade. Call me Greg.”

            John shook his hand, “John Watson,” He answered, forgoing the ‘Commander’ part since the officer did the same, “With c-sec?”

            Greg gave a shrug, “That’s why Sherlock puts up with me.” He chuckled, “And vice versa, I assure you.” His laugh died suddenly as he looked John over again, “Wait, not Commander Watson?”

            John was surprised at the familiarity the man already had with his rank. Hopefully, Sherlock wasn’t one to kiss and tell, “Yes, have we met before?”

            “No, but I know your Lieutenant. Sally.” He reassured, “She didn’t tell me everything, but last I heard you were shot and were being rehabilitated.”

            “Something like that.”

            “Well,” Greg gave his back a friendly pat, “It’s good to see you well. Sally was quite worried.”

            John nodded, remembering the earnest face and the rather aggressive way she tended to worry. He hadn’t realized how much he missed the crew until then.

            “Clearly, Sherlock found you. Talked to you, has he?” He winked. John didn’t know what to make of it.

            “Hardly.” John answered.

            “Oh, surely the pleasantries can wait ‘til the crime scene.” Sherlock snapped, already impeccably dressed, hair in order and eyes shining. He looked like a child on Christmas morning.

            “I’m not shaking hands over a dead body, Sherlock.” Greg responded, glumly. It looked to John that this was the typical banter.

            “You coming or not?” Sherlock barked over his shoulder. John hadn’t realized they were already steps away from the door.

            “What?” both he and Greg managed to ask.

            “I need him with me at the scene, Lestrade.”

            “And why is that?”

            “You simpleton, don’t you see?” He dramatically clenched a gloved hand, “the numbers of people who know whatever it is they are being killed off for is dwindling. John not only needs my help, but your protection.”

            “What?” John protested, “Wait a minute. I need no protection. I’m perfectly capable-“

            “As were your captain and the captain killed only a few days ago and how did that work out, Commander?”

            Greg sighed, already giving in, “If you’re seeing a connection between what happened to John and what’s happening now, I’ll trust that. Just please don’t make me regret it.”

            Sherlock’s posture relaxed and his face contorted to that of a pleasant –albeit dangerous –smile, “Your trust is appreciated, Lestrade. I can see why Mycroft takes to you.”

            John watched as Greg’s face turned a nice rose hue, “Who’s Mycroft?”  

            “Do hurry up, John!” Sherlock shouted with glee, “There’s a case on!”

            John wagered he had no choice. He followed the over excited detective and the embarrassed officer out the front door bypassing a humming Sherrinford who wished them a success on the case.

**Notes for the Chapter:**

> Just to let you know...Captain Anderson is actually a character from Mass Effect, not to be confused with Anderson from Sherlock. My inspiration for Sherrinford was Glyph from Mass Effect 3: Citadel. I never thought an info drone could be so funny. I knew that having one annoy Sherlock and yet mother hen him would be super awesome and a great asset for the story later. 
> 
> Also, any confusion on the krogan rebellions and rachni wars can be solved with mass effect wikia. It covers anything you need to know, other than that, I hope I didn't confuse anyone!


	3. Chora's Den

**Summary for the Chapter:**

> John had been to his fair share of clubs in the galaxy, but there was something distinctly...special about this one. It smelled, well, it had a distinct smell to it and perhaps if it had been entertaining guests as it usually did, it may have looked more appealing.

**Notes for the Chapter:**

> Apologies that this is going un-edited by a beta.

John had been to his fair share of clubs in the galaxy, but there was something distinctly...special about this one. It smelled, well, it had a distinct smell to it and perhaps if it had been entertaining guests as it usually did, it may have looked more appealing. The central round bar was the first thing John noticed, the asari dancer on the platform above it, the second. She fidgeted clearly uncomfortable with the half dozen c-sec officers pacing around the club.

            “What can I do for you boys?” A rather smug brunette man with a military hair-cut greeted them as they entered. His jaw tightened and eyes narrowed, expression instantly changing once he noticed Sherlock.

            “Fist,” Sherlock’s lips turned up slightly, “How’d your last transaction of red sand go? Pleasant, I expect. That is a new pistol, is it not?” At that, Fist mirrored Sherlock’s smirk.

            “Why Sherlock,” He said with enough contempt to get across how much he didn’t like having him there, “I have no idea what you’re talking about. Why you ask? Back to your old habits?”

            John was perplexed. Old habits?

            “Alright, cut it out,” Lestrade waved his hand in agitation, “We’re not here for you, Fist. We’re here about the commander. We need to speak to your bartender and some of the patrons here. I’m certain this would not be a problem for you.” John was astounded to see how swiftly the relaxed demeanor of the c-sec officer change to that of unquestionable authority.

            Fist didn’t seem particularly bothered by Lestrade. He merely nodded, gesturing to the scene behind him, “Just don’t harass any of my customers.” As if suddenly losing interest in his interaction with Fist, John watched amused as Sherlock’s eyes locked on the crime scene, an expression of glee shaping his face. Without another word and a last glance at his company, he was marching over with an air of importance about himself. John snorted momentarily forgetting that a dead body sat not a few feet away though Lestrade didn’t seem to mind.

            “I’m going to take a wild guess and say his enthusiasm for murders is underappreciated by the c-sec officers.” John commented, watching intently as Sherlock crouched over the slumped form of the dead commander, who appeared to have been a drunk whom merely fell asleep in the corner of the bar. Sherlock lifted what appeared to be a glass drink in his gloved hand and took an exaggerated sniff. John heard Lestrade’s exasperated sigh.

            “You have no idea.” He stressed, looking all the part tired from what must have been a significant amount of time associating with the man, “But believe it or not, you’re lucky he’s taking on this case. He overheard Sally telling me what happened and of course took it upon himself to get involved,” He seemed to be troubling over a thought before he spoke, “Do you really think something big is going on here?”

            John kept his eyes on Sherlock, who was at this point, moving on to glaring at the dead man as if affronted by his mere means of death, “I couldn’t tell you anymore from what I know and have seen in my brief experience,” He said stiffly, “The attack on my ship and her crew was executed flawlessly, masterly planned and there was a clear motive. This wasn’t a mindless ambush by ex-alliance or mercenaries. Something that well-orchestrated can only be working at a larger objective.” Before the conversation could deteriorate into something John wasn’t comfortable with, the conversation was interrupted.

            “Commander!” Sherlock barked, “I need your assistance.” John physically jolted at the call, but nonetheless obediently walked over, shoulders set as if following an order from a superior. When he was close enough, Sherlock regarded him silently before speaking, “You have a medical background.”

            “I-“John frowned, “How did you know that?”

Sherlock hummed in triumph, “Even at a distance, I could see you assessing the cause of poison. Discoloring of the skin, swollen glands, bloated face, all symptoms acknowledged, am I right?”

            John, to his own surprise, nodded. It was an automated response, conditioned in emergencies and endless times of crises he faced in the last decade. How Sherlock could notice that from yards away was-, “Quite impressive.”

            Sherlock seemed to freeze, eyes darting at him as if not sure how to take the compliment, “Well-“ He cleared his throat at a loss for words.

            “I’ve seen this before.” John spared Sherlock the embarrassment of recovering from the statement. At this close range, he could smell the tang of copper and strong alcohol. He noted the form of the dead commander, “This wasn’t a violent death. The man would have fought and collapsed. Instead, he slumped over as one does when they fall asleep.” His eyes briefly met Sherlock’s to see if he still had his attention. He got a nod to continue, “His killer did not want to cause a scene, either because they needed a quick escape or they aren’t the type that do well in a shoot-out.”

            “My dear Commander Watson, no wonder there are men trying to kill you.” John started at the unexpected reciprocated compliment. Sherlock ignored his reaction, raising his voice for Lestrade and the other c-sec officers to hear “What we’re looking for is a killer who would have been able to slip in and out without raising suspicion. Someone who either wasn’t capable of using firearms or would have caught too much attention if they were seen carrying. Any thoughts Lestrade on what kind of suspect that could be?”

            Lestrade blinked, “Just about anyone, Sherlock. The patrons here vary from all walks of life including some of the officers here. You know that.”

            Sherlock, sighed looking for all the world as if he was given no choice but to explain something rather simple to a child, “These walks of life you speak of are usually armed. Chora’s Den is a cesspool for violence and drug affairs as you’re clearly aware of, so it is not uncommon to see those of less reputable character partake in its comforts,” He paced in front of the body, putting some of the other officers at unease in their attempts to secure the crime scene, “So who –we ask –would look _unsuspicious_ without a weapon.”

            John’s eyes darted up to the nervous dancer above the bar, his thoughts clicking together, “Those that work here, I’d wager. The performers or the bartenders.”

             “My god, a wounded Alliance officer can do your jobs!” He belted to the rest of the officers being met with an army of glares.

            Lestrade scrubbed a hand over his face in obvious agitation, “Let’s start on the bartender then.”

*

            After what –predictably to John-was an unilluminating set of interviews, Sherlock left the scene in a huff of exclamations of “Dull!” and “Complete waste of time!”, giving John no choice but to pursue him to the entrance of the club where Sherlock had took to stopping in mid-thought.

            “Where have you seen it?”

            “Seen what?”

            Sherlock scowled, “Oh, don’t be slow. It’s pedestrian and annoying.”   

            “My apologies,” John humored, “My telepathy hasn’t been all that great of late.” When he was met with a rather impressive glower, he sighed, “Care to elaborate to a simple-minded drone?”

That seemed to actually work, “You’ve seen the effects of that same poison. Where?”

John didn’t like thinking much of his confidential foray into his military affairs, but nonetheless there was a lot that had been exposed to him during that time, one being the back worlds of the Terminus System, “I spent some time in Omega.”

“That’s a far way to be for an Alliance officer.” Sherlock knowingly commented, but before John could deny anything, he moved on, “The typical victims?”

“Mostly mercenaries, but all were connected to Aria T’Loak.” Aria, as John remembered her, was in so much words the ruler of the rock space station that was Omega. It really was no surprise that any event that was occurring there, the asari had her hands in or at least, had some knowledge of. At her name, something seemed to set Sherlock’s eyes alight, “Care to share?”

“It’s clear the bartender had no idea what had happened to the commander until an hour after his death, neither did the asari dancer. Her guilt is merely related to her associations with the Eclipse mercenaries and their smuggling of illicit drugs into Citadel via the club.” Sherlock tossed the information off-handedly.

“I’m sure c-sec would want to know that.”

“Boring.” Sherlock huffed, “It isn’t anyone currently here, but it is an employee. Someone who could easily and consistently elicit the poison.”

“Consistently?”

“Like you said, if it were a violent poison, he would have been on the floor. There would have been a scene. The commander died without a fuss. What poison do we know kills so violently, but silently? Something that needs to be administered over time.”

“Alright, so we would need an employee schedule for the last few weeks, match it up to the times the commander visited the bar.” John added.

“Indeed.” Sherlock merely replied, lifting his left arm and revealing the glow of his omni-tool. His fingers flew over some holographic keys before a file flitted up into view releasing a list of names and times.

“You did not.” John stated flatly, knowing already that if a man could break into his place of residence, he would find no qualms hacking into an establishment’s intranets.

 Sherlock looked up from the list, the orange haze of the hologram giving the pallor of his skin an unnatural golden glow, “Problem?”

 

*

            Sometime later Lestrade leaned back in his chair, the leather groaning from the shift of his weight, “Commander Martin Argus serving under the _SSV Gradient_ was –prior to his death –on shore leave while his recently assassinated captain was meeting with ambassadors for an important nondescript meeting in the Presidium some weeks ago. From some regulars at the bar, we place him in Chora’s Den on regularity of terran time about every 24 hours making his visits daily and prompt. He had been known to keep to himself, sitting in the same spot and ordering the same drink,” Lestrade overlooked his notes briefly to confirm a piece of information, “A krogan drink called Ryncol that can be altered for easier human consumption without knocking you flat out.”

            “So, a drink that is potent in taste that if it were to be poisoned, it would hardly be noticeable.” John commented, leaning against the frame of the doorway of Lestrade’s office.

            “Quite clever.” His palms pressed together and tucked under his chin, Sherlock blindly traipsed the office with his eyes closed, not hitting a single object in his wild maneuvering, “Each attempt was customized, catered to the individual.”

            “You’re still on about these all being related?” Lestrade appeared unconvinced at this point. John himself had seemed to forgo the idea momentarily that he was connected to this after the show Sherlock pulled at Chora’s Den.

            “It’s obvious!” Sherlock waved an arm animatedly, “The manner of death and place is smoke and mirrors hidden from any fool. You see unrelated deaths, whereas if you’d observed, you’d know that this is massive and _exciting_!”

            A thought occurred to John, “If this is what you say this is, these killers aren’t all the same person.”

            “No, they’re not. They numerous, set apart and synchronized like a…network.”

            “And this last one?” Lestrade asked.

            “Asari. Clever, blends in easily, and wouldn’t have been suspicious without a weapon. Had to be unassuming to get as close as she did to a Commander, perhaps was even friendly with him.”

            “Okay. That’s a start. We’re looking for an Asari who may have spoken often with the commander.”

            “She’s far gone by now.” Sherlock rapidly dismissed.

            “That may be, but at least we can get an identity of her-“

            “Irene Adler.” Lestrade threw up his hands at the interruption.

            John agreed with Lestrade’s vexation about Sherlock’s methods, but he could understand why the man continued working with detective. His tenacity was great and his skill even greater. They already had a lead and if this was a way for him to get one step closer to finding out just what happened to him and his crew when they were ambushed, then he didn’t mind following this wild man to the ends of the galaxy if he had to.

 


End file.
